Sources of Deforestation in Tropical Developing Countries

/ Key causes of tropical deforestation are investigated using cross-sectional data for 90 developing countries for the period 1981-1990. Regression results reveal that deforestation is associated with both development and scarcity. Deforestation accelerates with expanding infrastructure, trade, debt, investment in the human capital base, and resource-based economic expansion. On the other hand, absolute and relative scarcities-manifested by growing population pressures, food and land shortages, fuelwood dependency, and inequalities in access to land-are also key factors explaining forest loss. Thus, results point to a fundamental environmental conundrum: Development is required if countries are to alleviate scarcity-driven forms of forest exploitation but is itself a major cause of deforestation. Can countries balance development goals with forest protection? Setting aside the issue of its practical realization, the paper concludes that forest sustainable development cannot be achieved by implementing simple technical improvements in land-use practices alone. Securing the foundations for the sustainability of the forest base will require that countries address the underlying social processes driving tropical forest loss as well.KEY WORDS: Tropical deforestation; Developing countries; Rural land-use practices; Development; Scarcity.     

Economic and equity implications of land-use zoning in suburban agriculture

A cash-flow viability model is used to evaluate the impacts of land-use zoning on farm households in New Jersey. Findings suggest that zoning results in increased production expenses, lower efficiency and profitability, and the devaluation of land assets. Cash flow and economic viability are, thus, reduced. Impacts of zoning on farm incomes, off-farm incomes, revenues from land sales, indebtedness, and farm sizes were not statistically significant. The results suggest that the use of land-use zoning statutes to guarantee the existence of agriculture may not be equitable unless transferable development rights or other methods of compensating farmers for their losses are simultaneously implemented.     

经济增长方式转变与节约利用土地研究

在当前努力实现经济增长方式转变的过程中,经济方式的转变与节约利用土地资源的关系有待探讨。经济增长方式的本质内容是生产要素的组合和使用方式。转变经济增长方式,即从依靠生产要素的数量扩张而实现的粗放型经济增长,转变为依靠生产要素的效率提高而实现的集约型经济增长[1]。土地作为社会经济发展的重要要素之一,对土地资源的节约利用是实现集约型经济增长的重要内容之一,同时节约利用土地资源对经济增长方式的转变起着重要的促进作用。     

黄土高原半干旱区侧柏林群落土壤呼吸日变化及季节动态变化特征

Desertification is one of the most serious eco-environmental problems around Qinghai Lake. Based on GIS and RS, GIS analysis was used to obtain the information of spatial-temporal change and different pattern of desertification in each county around Qinghai Lake in four phases of 1976, 1987, 1995 and 2006. Using the function of intersect and overlay supported by ARCGIS, with analyzing attributes of vector RS images, we obtained transition data and established transfer matrix of land-use types in recent 30 years, besides, protracted land-use transition maps of all desertification classes. In further, we analyzed transition quantity and direction of desertification in each county, moreover, reconstructed the process of spatial-temporal evolution of desertification. The results are showed below: (1) it′s the transition between desertified land and others but not in the desertified that played the main role in Gangcha and Gonghe County, while the transfer between desertified lands were greater than that with other land-use types in Haiyan County. (2) Extremely severe desertified land mainly distributes in Ketu and Sand Islands that belongs to Haiyan County, and moderate desertified land in riversides of Gangcha County, also, the light desertification expanded too rapidly to become the most desertified land-use type in the surrounding of Qinghai Lake since 1976. (3) By using relative change rate of desertified land, the regional variability rank from top to toe was Gangcha, Haiyan and Gonghe.     

大城市土地利用优化与抗震防灾规划

随着城市人口的增加和工业化、城镇化水平的提高，导致非农建设用地需求增大，人地矛盾日益突出，盲目增加建设用地需求量，会增大城市的危险性系数。采用地理信息系统技术，在分析北京市地震烈度对土地影响的基础上，对土地利用的数量结构和空间结构进行了优化，以实现对土地资源的合理利用、安全规划和优化配置。     

城乡交错带土地利用研究——以芜湖市为例

城乡交错带是城市扩展和农村发展的前沿,也是统筹城乡关系的重点地区。选择芜湖市城乡交错带为研究区域,利用2004年土地利用数据分析了芜湖市城乡交错带地域土地利用的现状和存在的主要问题及其原因,探讨了2006年辖区调整后该地域土地利用的对策与措施。     

醴陵市土地利用与生态环境建设问题研究

在阐述醴陵市土地利用和生态环境现状的基础上,分析了醴陵市土地利用中存在的主要问题,对生态环境现状进行了评价,并提出了醴陵市生态环境建设与保护的战略步骤和措施。     

基于土地利用变化的生态服务价值损益估算--以大庆市为例

土地利用／覆盖变化遥感研究表明，大庆市自1988年以来土地利用状态变化很大，由此引起了该区域生态环境的一系列响应及其生态系统服务价值的变化。以大庆市1988年和2001年的Landsat TM图像解译数据为基础，应用Costanza等人对全球生态系统服务价值的测算方法，分析了该市土地利用变化及其所引起的生态系统服务价值的变化。研究结果表明，13年间，大庆市土地利用的变化损害了该区域生态系统的生态服务功能，使生态系统服务价值损失了20．76％-24．01％。     

TIM: Assessing the sustainability of agricultural land management

TIM (Threat Identification Model) is a framework for the ex ante assessment of agricultural land management sustainability at the land unit scale that identifies sources of unsustainability within agricultural land management systems. The model explicitly links defined hazards to land productivity and environmental integrity, land resource data and information, and land management practice options using expert and local knowledge on land management and its potential effects. The model was tested in the Crystal Creek Subcatchment, a narrow coastal strip of land situated in north Queensland, Australia. This area was chosen due to the expansion of the sugar industry onto increasingly marginal land in the area, which represents a threat to sustainable land use and a requirement for careful land-use planning and land management.TIM may be used in a relational database as a stand alone decision support system for land-management planning. Its usefulness in land-use planning is greatest when it is linked to a Geographic Information System (GIS) as shown in this paper. GIS allows TIM outputs, such as constraints to agriculture and site-specific best-management practices, to be identified in a spatially explicit manner.The main advantages of TIM are that it can be done ex ante, it removes the need to define sustainability assessment criteria and indicators, it utilises current understanding of the causes and effects of land degradation and how different land-management practices influence these, and links this knowledge to definite land-management options.     

Efficiency and Concordance of Alternative Methods for Minimizing Opportunity Costs in Conservation Planning

Abstract:  Scarce resources and competing land-use goals necessitate efficient biodiversity conservation. Combining multicriteria analysis with conservation decision-support tools improves efficiency of conservation planning by maximizing outcomes for biodiversity while minimizing opportunity costs to society. An opportunity cost is the benefit that could have been received by taking an alternative course of action (i.e., costs to society of protecting an area for biodiversity rather than developing it for some other use). Although different ways of integrating multiple opportunity costs into conservation planning have been suggested, there have been no tests as to which method is most efficient. We compared the relative efficiency of 3 such procedures ( Faith & Walker [1996] , Sarkar et al. [2004] , and a procedure of our own design) in a systematic conservation-planning framework for the Milne Bay Province of Papua New Guinea. We devised 14 opportunity costs and assigned these to 3 scenarios representing different conservation planning concerns: food security, macro-economic development, and biodiversity persistence. For each scenario, we compared the efficiency of the 3 methods in terms of amount of biodiversity protected relative to total expenditure for each opportunity cost. All 3 methods captured similar amounts of biodiversity, but differed in total cost. Our method had the least overall cost and was therefore most efficient. Nevertheless, there was a high correlation and geographical concordance among all 3 methods, indicating a high degree of spatial overlap. This suggests that choosing an appropriate approach may often depend on contextual factors related to the design of the planning question, rather than efficiency alone.